New addition has been sided already. The interior walls are still open. What do you recommend for mounting the exterior coach lights?

Apancake box or 4" round work box?

It will be covered from a 7x7 plastic siding block pre notched to match the siding.

Either will work, which ever works best with the trim block.

Look for trim mounting blocks with built in boxes.

Siding Mounting Kits with Built-in Box (http://www.arlcatalog.com/Siding/Siding%20Mounting%20Kits%20with%20Built-in%20Box.htm)

Breeze through the Arlington catalog, they make some neat stuff.

Stuff I wish I thought of.

Either will work, which ever works best with the trim block.

Look for trim mounting blocks with built in boxes.

Siding Mounting Kits with Built-in Box (http://www.arlcatalog.com/Siding/Siding%20Mounting%20Kits%20with%20Built-in%20Box.htm)

Breeze thru the Arlington catalog, they make some neat stuff.

Stuff I wish I thought of.

I was hoping to daisy chain 7 fixtures without adding an extra junction box in the crawl space(attic)

Using the arlington siding blocks with the built in box hard to tell if there's enough rm for more than 1 12-2?
I know if I use the pancake mounted to the siding, that I'll have to make drops for each fixture. Which is why I'm considering 4 1/8 hole saw cutting all the way through an using a 4" round box

Good plan, do it.